Integrated Dental Implant Abutments

ABSTRACT

A dental abutment having a coronal portion for supporting a prosthesis separated from a post for seizing, galling or cold welding in a dental implant by a cylindrical portion and hemispheric base portion of length less than the combined length of the prosthetic head and locking taper post portions. The hemispherical portion of the abutment having a sloping shoulder with a surface that forms a small angle with a perpendicular to the cylindrical surface. A dental prosthesis system including such dental abutments.

RELATED APPLICATION

This application is a Continuation of U.S. application Ser. No.14/591,654, filed Jan. 7, 2015, herein incorporated by reference in itsentirety.

FIELD

The present disclosure concerns dental implant abutments.

BACKGROUND

Dental implants are often the best treatment for missing teeth. When adamaged or decayed tooth is removed, both the visible part of the tooth,called the crown, and the root are lost.

A dental implant can be placed in the jawbone so that it can be fusedwith natural bone and become a strong and sturdy foundation forreplacement teeth. Implants can be used to replace an individual toothor for an implant-supported bridge or denture containing multiple teeth.

A dental implant abutment is a device that connects the prosthetictooth/teeth to the dental implant. The replacement tooth is custom madeto match a patient's natural teeth and is sometimes referred to as acrown or dental prosthesis.

SUMMARY OF THE INVENTION

This disclosure describes dental abutments that can not only be used forall conventional restorative techniques, but can also be readily scanneddigitally, which enables precise restorations of a tooth or teeth to befashioned more easily and conveniently than abutments whose geometrypreclude the use of digital scanning or require modification orinterpretation of scanned images for use. This feature supports themovement of the dental implant field toward precise customizableprosthetic restorations and digital dentistry with the increased use ofCAD/CAM technologies.

The dental abutments described within can also include anti-rotationalfeatures for the prosthetic component (i.e. crown) that allows thepatient's prosthesis to have a precise fit. Grooves on opposite sides ofthe coronal end of the abutment (i.e. longitudinal end of abutmentlocated farthest from the bone in the implanted site) provide theanti-rotation element. Each groove is generally of a constant depth thatslopes toward the shoulder to end the anti-rotational element. Thesloping of the groove is symmetric to reduce material stress. Thecoronal end of the abutment can also have a rough surface (e.g., agrit-blasted surface) to facilitate retention. For example, gritblasting can provide asperities up to 300 microns in size. The term“asperities” is used to indicate sharp, rough, or rugged projectionsextending from a surface.

The described dental abutments have a post in the area of the apical endof the abutment (i.e. longitudinal end located closest to the bone inthe implanted site) that is received by the open end of the dentalimplant. The post allows for a 360° of rotation during seating toincrease the likelihood of correct orientation of the abutment, orabutment-restoration unit, either intra-orally or extra-orally. This360° rotation also facilitates parallelism for angled abutments. Thepost and implant connection utilizes a friction fit connection which isa locking taper. Once fully engaged, this mechanism limits or preventsunintentional rotation between the dental abutment and implant and canprovide a bacterially sealed connection. The post has a cylindricalshape for simplicity and compatibility with a large number of dentalimplants.

Some dental abutments include a coronal portion that slopes to ashoulder of the dental abutment after a fixed distance of at least a 15°angle to allow for the scanning to be performed without any additionalmodifications or interpretations to the scan. The distance from thecoronal end to the shoulder and the shoulder width has a ratio of lessthan seven with a shoulder width of greater than 0.02 inches. The teamthat developed the present dental abutments has found that the width ofthe shoulder and the ratio between the distance from the coronal end tothe shoulder and the shoulder width to be particularly significant inproviding an abutment that is conducive to digital scanning. The coronalportion slopes toward the shoulder of the dental abutment at about a 3°angle to allow the anti-rotational element to work properly.

In some dental abutments, the distance from the bevel at the coronal endto the top of the hemispherical shoulder is long enough to allow all theedges of the dental abutment to be digitally scanned without additionalmodifications or interpretations. In contrast, other dental abutmentshave margins that are not smooth and/or not visible on scans so usersmanually draw in the margin on the scan results.

The geometry of these dental abutments also allows for one conventionalrecording sleeve configuration to suffice for registering multipledifferent abutment dimensions, since different abutment sizes andangulations are independent of the prosthetic attachment aspect of theabutment. Conventional dental impression materials can be used to recordand represent multiple different abutment dimensions prosthetically.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1A and 1B show a dental implant and dental abutment before andafter the addition of a crown, respectively.

FIG. 2A is a side view of a dental abutment. FIGS. 2B and 2C depict thecross section and coronal views of the abutment in FIG. 2A,respectively.

FIGS. 3A and 3B show two dental abutments of different sizes with andwithout a crown.

FIGS. 4A and 4B show two dental abutments of different configurationswith and without a crown.

FIGS. 5A-5C show a dental prosthesis supported by multiple dentalabutments.

FIGS. 6A and 6B are, respectively, a front view and a sidecross-sectional view of an angled dental abutment

DETAILED DESCRIPTION

FIG. 1A shows a dental abutment 100 engaged in a dental implant 110which has been placed in a patient's jawbone 112. FIG. 1B shows thedental abutment 100 and the dental implant 110 after a crown 114 hasbeen placed on the dental abutment 100.

The dental abutment 100 in FIG. 1A extends from the apical end 116 (i.e.toward the jaw) to the coronal end 118 (i.e. toward the crown) in thelongitudinal direction. The dental abutment 100 has a post 120, which isdesigned to be received by the open end of the dental implant 110. Thepost 120 extends from the apical end 116 of the dental abutment 100 to aretention element 122. The dental abutment 100 also has a coronalportion (or head) 123 which designed to support the crown 114. Thecoronal portion 123 extends from the coronal end 118 of the dentalabutment 100 to the retention element 122.

The dental abutment 100 can be made out of a variety of materials,including titanium alloy or polyether ether ketone (PEEK).

FIGS. 2A-2C shows the dental abutment 100 in isolation to more clearlyillustrate features of the dental abutment 100.

The post 120 is substantially cylindrical, which allows for the 360°rotation of the dental abutment 100 while it is being seated into thedental implant 110 (see FIGS. 1A and 1B) in order to facilitate adentist's correct orientation of the prosthesis or crown 114 (see FIG.1B), either intra-orally or extra-orally. This cylindrical shapeprovides the opportunity for the prosthesis to be used to orient andinitially seat the abutment in the well of the implant. The simplicityof the cylindrical shape affords for improved manufacturability and alsomakes the dental abutment 100 compatible with a number of differenttypes of dental prostheses. While substantially cylindrical, the post120 is tapered to provide a friction fit connection which is a lockingtaper between the post 120 and the dental implant 110 (see FIGS. 1A and1B). This configuration can facilitate seizing, galling or cold weldingbetween the post 120 and the dental implant 110.

Once fully engaged, this mechanism limits or prevents unintentionalrotation and micro-movement between the dental abutment 100 and dentalimplant 110 (see FIGS. 1A and 1B). The locking taper can also provide abacterial seal between the two components. The angle α between sides ofthe post 120 and a longitudinal axis 124 of the dental abutment 100 isapproximately 1.3°. Depending on the dental abutment variant, the anglebetween sides of the post 120 and a longitudinal axis 124 of the dentalabutment 100 is typically between 1.1° and 1.6°. The geometry of thedental abutment 100 is symmetrical along the longitudinal axis 124.

The retention element 122 extends from the post 120 to the coronalportion 123. The retention element 122 has a base 128 and a shoulder 130which meets the base 128 at a margin 132. The transition between thebase 128 and the post 120 is a curve 134 with a radius of curvature 136(see FIG. 2B) of approximately 0.02 inches. In some dental abutments,the radius of curvature 136 is more or less than 0.02 inches (e.g.,between 0.01 and 0.03 inches) which can reduce stress factors andresulting fractures. The surface of the base 128 has a radius ofcurvature 138 (see FIG. 2B) of approximately 0.08 inches. In some dentalabutments, the radius of curvature 138 is more or less than 0.08 inches(e.g., between 0.08 and 0.15 inches). The shape of the base 128 providesfor the consistent confrontation of what is an approximation of ahemispherical contour to tissues in the proximity to the periosteum.This confrontation in turn can stimulate osteoblastic activity andsubsequent bone growth.

Between the hemisphere and the shoulder 130, the side of the abutmentextends for a length L₁ to the margin 132. The perimeter (e.g.,circumference) of the dental abutment increases at 1-2° in this portionof the dental abutment as distance from the apical end 116 of the dentalabutment 100. In the dental abutment 100, the length L₁ is 0.16 inches(4 mm). As discussed in more detail below with reference to FIGS. 3A and3B, some dental abutments are configured in which the length L₁ is moreor less than 0.16 inches (4 mm) (e.g., between 0.05 (1.3 mm) and 0.32inches (8.1 mm)). This variability provides the opportunity to use thesame inferior or post and superior or head contours on the abutment,while providing the flexibility to use with implants placed at differentdepths within the jaw bone.

The diameter of the dental abutment at the margin 132 is 0.24 inches (6mm). In some dental abutments, the diameter of the dental abutment atthe margin 132 is more or less than 0.24 inches (6 mm) (e.g., between0.16 inches (4 mm) and 0.31 inches (8 mm).

An angle θ is defined between the shoulder 130 and a plane 140 that isperpendicular to the longitudinal axis 124. In dental abutment 100, theangle θ is approximately 15°. In some dental abutments, the angle β ismore or less than 15° (e.g., between 10° and 20°). It has been foundthat dental abutments in which the angle β is approximately 15° allowthe scanning to be performed without any additional modifications orinterpretations to the scan.

The coronal portion 123 includes a neck 142, an anti-rotation portion144, and a bevel 146 at the coronal end of the dental abutment 100. Theneck 142 has a length La. The neck 142 is substantially cylindrical withsides that are substantially parallel to the longitudinal axis 124 ofthe dental abutment 100. Some dental abutments have necks with othershapes such as, for example, with rectangular or octagonal (rather thancircular) cross-sections.

In contrast, the anti-rotation portion 144 of the coronal portion 123 istapered with a cone angle γ such that the perimeter (e.g.,circumference) of the coronal portion 123 at the coronal end of theanti-rotation portion 144 is smaller than the apical end of theanti-rotation portion 144. In dental abutment 100, the cone angle γ isapproximately 3°. In some dental abutments, the angle γ is more or lessthan 3° (e.g., between 2.5° and 3.5°). It has been found that dentalabutments in which the angle γ is more than 2.5° help enable scanning tobe performed without any additional modifications or interpretations tothe scan.

The surface of coronal portion 123 can be either rough or smooth basedon the individual needs dictated by the procedure. A roughened surfacecan be achieved, for example, through the use of grit blasting. Thisprovides a better surface for the adhesion of dental materials, such asopaque (i.e., composite dental resin that is used to cover unsightlydentition), as well as the crown 114 or prosthesis to the coronalportion 123. In particular, the roughened surface can facilitate themechanical retention of chemical bonding agents such as opaque layers ofcomposite resins or prosthetic cementing agents.

The structure of the coronal portion 123 provides the dental abutment100 with a configuration that can be easily scanned. The perimeter(e.g., the circumference) of the dental abutment 100 increasesmonotonically from the coronal end 118 to the margin 132 defined betweenthe base 128 and the shoulder. The edge between the bevel 146 and theanti-rotation portion 144 is smaller than the edge between anti-rotationportion 144 and the neck 142. The edge between the anti-rotation portion144 and the neck 142 is smaller than margin 132 between the neck 142 andthe base 128. As can be seen best in FIG. 2C, the shoulder 130 isvisible and clearly delineated which makes the shoulder 130 easy torecord during digital scanning. In addition, the length L₃ (from thebevel 146 to the neck 142 of the coronal portion 123) is long enoughthat when present in concert with angle γ, allows all the edges of thedental abutment to be observed with a digital scanner without additionalmodifications or interpretations to the scan. Unlike abutments whosegeometry preclude the use of digital scanning or require modification orinterpretations of scanned images for use, the abutments presented inthis application allow for easy digital scanning which enables the rapidand precise restorations of a tooth or teeth. This feature supportsmovement of the dental implant field toward customizable restorations orprostheses and digital dentistry with the increased use of CAD/CAMtechnologies.

The geometry of these dental abutments not only facilitate theirrecording by digital scanning technologies, but also allows for asingular conventional recording sleeve configuration to suffice forregistering multiple different abutment dimensions. Further conventionaldental impression materials can be used to record and represent theirmultiple different abutment dimensions prosthetically.

The anti-rotation portion 144 of the coronal portion 123 includesanti-rotation features in the form of two grooves 148 on opposite sidesof the coronal end 118. The anti-rotational features help control theorientation of a prosthetic component or crown 114 which helps provide aprecise fit of the prosthesis. The grooves also guide the prostheticcomponent or crown 114 into the correct orientation.

The anti-rotation grooves 148 located on opposite sides of the coronalend 118 of the dental abutment 100 are generally of a constant depththat slopes toward the shoulder to end the anti-rotational element. Thesloping of the groove is symmetric to reduce material stress.

The length L₃ (see FIG. 2A) of the anti-rotation portion 144 and thegrooves 148 are nominally 0.125 inches (3.2 mm). The width W (see FIG.2A) of the grooves 148 is nominally 0.055 inches (1.4 mm). The depth D(see FIG. 2B) of the grooves 148 is nominally 0.02 inches (0.51 mm). Asdiscussed above, the anti-rotation portion 144 of the coronal portion123 is tapered with an angle γ of approximately 3°. The angled surfaceallows the anti-rotational element (e.g., grooves 148) to work properly.In addition, the sloping surface facilitates attaching other componentsas it is difficult to attach additional components to parallel surfaces,

Some dental abutments have grooves 148 in which the length L₃ is more orless than 0.125 inches (3.2 mm) (e.g., between 0.1 (2.5 mm) and 0.3inches (7.6 mm)), the width W is more or less than 0.055 inches (1.4 mm)(e.g., between 0.04 inches (1 mm) and 0.06 inches (1.5 mm)), and/or thedepth D is more or less than 0.02 inches (0.51 mm) (e.g., between 0.010inches (0.254 mm) to 0.030 inches (0.76 mm)). Some dental abutmentsinclude other anti-rotation features such as, for example, hexagonal ormulti-sided flat surfaces and/or a variety of slots or grooves.

As discussed above, some dental abutments are configured in which thelength L₁ (between the hemispherical portion of the base 128 and themargin 132) is more or less than 0.16 inches (4 mm) (e.g., between 0.06inches (1.5 mm) and 0.32 inches (7 mm)).

FIGS. 3A and 3B compare the dental abutment 100 with a dental abutment200 that has a length L₁ that is 0.24 inches (˜6 mm). The dentalabutment 100 and the abutment 200 have identical configurations exceptfor the differences in the length L₁. In particular, the dimensions ofthe post 120 are the same in both the dental abutment 100 and theabutment 200 such that a single type of dental implant can be used witheither abutment. This configuration allows a dentist to set the positionof the coronal portion 123 of the dental abutment 100, 200 relative tothe gum above an implant regardless of the implant's axial position inthe jawbone 112.

Some dental abutments have retention elements 122 that have differentperimeters (e.g., diameters for the illustrated dental abutments). FIGS.4A and 4B compare the dental abutment 100 with a dental abutment 300 inwhich both length L₁ and the diameter of the retention element aresmaller than those of the dental abutment 100. It accommodates implantwells that are more parallel for greater retention or wider for greaterstrength and resistance to metal fatigue and breakage.

This specification has described a dental prostheses system includingversatile abutments with numerous advantages. Dentists may now makenumerous uses and modifications of and departures from the specificembodiments and techniques disclosed herein without departing from theinventive concepts. For example, multiple dental abutments as describedabove can be used to support a single dental prosthesis. FIGS. 5A-5Cshow a system in which four dental abutments 100 are used to support asingle dental prosthesis 114. In another example, dental abutments canbe formed with the features described above but with the post set atangle relative to the coronal portion. FIGS. 6A and 6B show a dentalabutment 400 in which an axis 124′ of the post 120 set at angle relativeto an axis 124″ of the coronal portion 123. Consequently, the claims areto be construed as embracing each and every novel feature and novelcombination of features presented in or possessed by the apparatus andtechniques herein disclosed.

There has been described novel apparatus and techniques in connectionwith dental implanting. It is evident that those skilled in the art maymake numerous modifications of and departures from the specificapparatus and techniques herein disclosed without departing from theinventive concepts. Consequently, the invention is to be construed asembracing each and every novel concept and combination of conceptsdisclosed herein and limited only by the spirit and scope of theappended claims.

What is claimed is:
 1. A dental abutment extending from an apical end toa coronal end along a longitudinal axis, the dental abutment comprising:a retention element with a base oriented towards the apical end of thedental implant and a shoulder oriented towards the coronal end of thedental abutment, the shoulder oriented at an angle of at least 12.5°relative to a plane that is perpendicular to the longitudinal axis suchthat the perimeter of the retention element increases with increasingdistance from the coronal end of the dental abutment through the regionof the shoulder; a post extending from the apical end of the dentalabutment to the base of the retention element; and a head extending fromthe coronal end of the dental abutment to the shoulder of the retentionelement, the head having a cone angle between 2.5° and 3.5°.